1998 Ford Windstar DX review from North America

False Door Ajar Warning Light and Chime- My 1998 Ford Windstar GL with 186K miles had this problem at 144K miles. This intermittent failure drove me nuts until I learned these facts that every Windstar owner must master: The Generic Electronic Module (GEM) above the gas peda1 monitors the ajar switches. A switch is “open” until the door is opened, causing the switch to close and form a current path to chassis ground. The door ajar switch in each door can get dirty, causing a “short” through the switch to chassis ground. It does not take much of a short; a little bit of dust along with high humidity will confuse the system. The door ajar warning light and the dome light will stay on with the door closed, and the chime may ding. Driving more than 15 mph will stop the chime. The problem usually can be fixed by spraying WD-40 into the latches one at a time while opening and closing the door and cleaning the contact on the sliding door with WD-40. The WD-40 leaves a coating that repels water and eliminates the short. If WD-40 does not work, you can replace the offending switch. To find the shorted switch, measure the resistance to ground of each door sensor circuit at the GEM. Wires IDs: Black/yellow = driver, Black/pink = passenger, black/white = sliding, black/light blue = tailgate.

The Windstar is the most reliable car I have owned.